I have only been around the Deaf community this year and have yet to engage someone enough to feel comfortable about asking for an 'atheist' or 'atheism' sign. Since it is the absence of something and signing is relative (mostly) to the act itself, I am bewildered to think what a possible gesture would be-besides an abbreviation or symbol that gestures something else, like how you were referencing 'think'.

I once saw a sign years ago, the handshape A going from the thumb touching the forehead into the space in front of the forehead. But this was shown to me by a hearing person and I have never personally seen a deaf person use this sign, plus the hearing person said that he was repeating it from another deaf guy who made it up, meaning only one person ever used this sign in the deaf community, so I've never really accepted it and seen it only as a curiosity. But I can see that by touching the forehead, that sign included the location morpheme used in some other ASL signs for the ASL signs THINK or MENTAL.

Maybe the sign that was shown to me for atheism was actually originally derived from the sign for LOGIC from SEE, but with the handshape A substituted for the handshape L. If that's the real origin of the sign, however, I have no interest in seeing a sign based on either Seeing Essential English (SEE1) or Signing Exact English (SEE2). I'd rather have a sign based on linguistic principles from ASL. I have no information that LOGIC is a sign from either variety of SEE and isn't from ASL, but it doesn't really look like an ASL sign. I've always assumed LOGIC to be an example of a SEE sign, but I couldn't tell you whether the sign actually comes from either SEE variety.

Have you seen the above sign, or other signs for atheism? This doesn't have to be an ASL sign.

If there are signs for atheism in other sign languages that anybody else in this group has seen, I'd be curious to see what those signs look like and which sign languages the signs came from.